I suppose that for those who care about higher resolution, you are mean to buy the "stunning book"
or attend one of the exhibitions
as advertised, rather than expect to get it for free and without effort!
Also, I just noticed that there is a better slide-show if you go to the actual awards site instead of through the Telegraph: http://bwpawards.org
and click on the "eye-con".
And if you cannot get to any of those venues, another option is a similar exhibition at the National Museum of Natural History in Washington:2012 World's Best nature Photography: Windland Smith Rice International Awards
Also with a book of course.